vfx-muzzle-flash

Create a Node3D at the weapon's barrel tip, attach a controller script that builds a billboarded quad with an additive star-burst shader, and call its fire() method on each shot. Connect the weapon's fired signal to fire() so the flash triggers automatically.

Use a spatial shader with blend_add and unshaded render modes, compute a radial core with smoothstep, and add spokes via cos(angle * ray_count) raised to a sharpness power. Billboard the quad in the vertex stage while re-applying node scale so per-shot size randomization works.

A single shader quad is the standard approach because a flash lasts only 60-100 ms, too short for particle animation to read. A small GPUParticles3D one-shot can optionally add sparks, but the core flash is one quad plus a brief OmniLight3D.

The shader's star orientation is fixed unless you randomize it. Set a random_seed shader uniform to randf() * TAU on each fire() call and vary the quad size by about 15 percent so every flash reads as a new burst.

Do not use it for continuous flames like a flamethrower, bullet impact sparks on walls, tracer lines from barrel to target, or slow spell charge-up glows. Those need dedicated fire, hit-spark, mesh-line, or magic-glow effects instead.

The controller preloads its shader at parse time, so a missing or broken shader file takes the whole script down. Check script errors after writing files, and use load() behind ResourceLoader.exists() for optional scenes like hit-spark instead of preload().